actinic light, ultraviolet light definition

Ultraviolet light (actinic light) is light that falls past the visible spectrum at the violet section and features wavelengths shorter than the wavelengths of visible light.  Light that encompasses ultraviolet radiation is said to be actinic, because it results in photochemical processes such as paint embrittlement, pigment and dye fading, and the creation of images on paper/photo film. Accelerated tests in labs use strong ultraviolet light for their procedures. Unfortunately, the ultravolet light part of direct sunglight has harmful influences on organic paint ingredients.  When manufactuers sell paints, they rate the stability of the materials based upon the presumption that the painting will be displayed in a place where the daylight hitting it is diffused.